1. Field of the Invention
This invention relates to an image editing apparatus, and more particularly to a method of automatically detecting a change or shift between different scenes of an image and an image editing apparatus which makes use of the method.
2. Description of tile Related Art
When an editing operation is performed for image information such as a video image, the editing operation is performed in most cases for each scene or shot of the video information. Also, when engaged in connecting a plurality of scenes to make up a single work, connection of the scenes is carried out after first deleting unnecessary portions, editing the image, processing the image, adding special effects and performing other necessary operations for each of the scenes.
In a movie or cinema, editing operations such as those mentioned above have been performed by coloring a film frame by frame or patching, that is, cutting and connecting, a film after photographing. Where image information is stored on a video tape, a video disk, a hard disk or a similar recording medium, the physical recording medium itself is not made a subject for editing, but rather, editing operations are performed for an image signal read out from the recording medium. As the image signal, a signal that has been processed by image compression processing is frequently used.
In order to perform an editing operation for an image signal, since an editing operation is performed in most cases for each scene, it is necessary to detect and record information regarding a starting time and an ending time of each scene in advance. Conventionally, an image is displayed using a frame feeding function of an image reproducing apparatus, and starting and ending Limes of each scene are manually written down one by one making use of time information incidental to input source data. This method, however, requires considerable labor and time for detection of a change or shift between scenes, resulting in a reduction of operation efficiency in editing operations.
An image editing apparatus is disclosed in Japanese Patent Laid-Open Application No. 268370/1990 (JP, A, 2-268370) by Katayama et al. wherein, using image data coded so as to allow progressive display as subject data, original image data are automatically edited in accordance with an editing procedure in which editing has been performed for low resolution data of this image data. With the apparatus, since a retrieving or editing operation by a human operator is performed for low resolution data, the time required for retrieval or transmission can be reduced. However, retrieval itself is still performed manually and considerable time is required for detection of a change-over between scenes. Japanese Patent Publication Application No. 29355/1991 (JP, B2, 3-29355) by Yuasa et al. discloses a method wherein a plurality of known image data are registered as reference image data in advance and object image data for comparison is compared with the reference image data to detect a scene change. With this method, however, since It is necessary to first register the reference image data, the reference image data must be prepared for each scene for which it is desired to perform retrieval. Consequently, the method cannot be applied to unknown image data.